A smart card assembly includes an integrated circuit component embedded within a polymeric card, typically a credit-card-sized assembly. The integrated circuit component contains information, such as access privileges, account balances, and security information. Smart card assemblies include electrical contacts at the surface of the smart card that permit electrical access to information stored in the integrated circuit component. The integrated circuit component is connected to the electrical contacts to allow a reader to make physical contact with the electrical contacts to permit the transfer of signals to and from the integrated circuit component for processing.
Contactless cards have been developed to allow utilization of the contactless card without physical contact with a mechanical reader head, thereby making the contactless cards faster to use and their functionality more transparent to the user. An antenna is typically disposed within the card to receive a signal transmitted from a base unit and to transmit a signal back to the base unit. In a contactless card, the integrated circuit component is typically embedded in the card, and is not attached to metal contacts at the surface of the card. In this manner, the position of the integrated circuit component is not based upon a need to be attached to contacts exposed at the surface of the card.
It is desired to form a microelectronic assembly that includes the functionality of both the contact card and the contactless card. Such dual interface smart cards, commonly referred to as combi-cards, include both contact pads at the surface of the card and contactless capabilities.
It has been difficult to achieve acceptable results with dual interface smart cards. The process of connecting the embedded antenna to the integrated circuit component that has been attached to the external contacts has been difficult to achieve reliably. One proposed solution has been to include two integrated circuit components within each dual interface smart card, one for the contact function and one for the contactless function. However, this approach leads to a more expensive smart card and a more complicated manufacturing process.
One approach that has been proposed is to laminate a polymeric card about an antenna, an integrated circuit component, and a contact pad. Such a technique is difficult to accomplish without damaging the components, due to the tight tolerances required during the lamination process and the relatively fragile components when subjected to the heat and pressure of the lamination process.
In typical smart card assemblies, the antenna is embedded within the card during a lamination step, and later attached to the integrated circuit component by forming openings in the laminated card to expose the antenna element within the openings. This leads to difficulties in processing and a complicated attachment process, as the integrated circuit component that is attached to the embedded antenna has to be connected to the contacts that are exposed at the surface of the finished card. In prior combi-card assemblies, this process has been accomplished in two steps, by first embedding the antenna and then making connection to the antenna within the polymeric card.
Therefore, a need exists for an antenna that can be directly attached to the integrated circuit component and contacts exposed at the surface of the combi-card and reliably formed in a polymeric card.